I've had an NPPL for about three years, now and haven't wanted to do anything that it won't let me do.
As bonniejack said don't bank on it being any quicker but the medical cost me a grand total of nothing and it's valid for about a century and a half, I've paid for the licence once and won't need to pay for it every five years. It's not for everyone but it works for me, my ideal flight is an evening or dawn bimble in a Cub and it's hard to get more than three passengers in the one spare seat.
The money I've saved on the medical (I could've got a Class 2 if I'd wanted one, but didn't) paid for my time with an instructor to keep it all legal.
UK only hasn't bothered me though there are those who have got clearance to fly overseas on an NPPL and they didn't explode or anything.
Yeah, the future and dear old EASA might change things but - here's a novel idea - they might even make it better.